I'd relatch her and she would suck but then start crying.
DS did this too - with the OALD, there were a couple of reasons, I think:
- he was used to immediate letdown, almost as he was latching, so he got frustrated when he had to wait at all.
- he liked the slower flow after letdown stopped being so forceful and then he'd be shocked by the second letdown.
GS is fun times with baby who's used to getting lots of milk immediately, they don't have to develop much patience and they're wondering what's going on - there's always been heaps of milk here, suddenly there's not, yk? To me, that signals that you have a good supply level - satisfies her most of the time and the GS is achieving what it should.